Add package dependents info

Cargo.toml

@@ -42,7 +42,7 @@ once_cell = "1.5.2"
 opener = "0.5.0"
 reqwest = { version = "0.11.18", features = ["blocking", "json"] }
 rpassword = "5.0.1"
-semver = { version = "0.11.0", features = ["serde"] }
+semver = { version = "1.0.17", features = ["serde"] }
 serde = { version = "1.0.116", features = ["derive"] }
 serde_json = "1.0.58"
 structopt = "0.3.18"

src/package_req.rs

@@ -16,7 +16,7 @@ use crate::package_name::PackageName;
 /// * `roblox/[email protected]`
 /// * `lpghatguy/[email protected]`
 /// * `foo/bar@1`
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct PackageReq {
     name: PackageName,
     version_req: VersionReq,

wally-registry-backend/Cargo.toml

@@ -28,7 +28,7 @@ reqwest = { version = "0.11.0", features = ["blocking", "json"] }
 rocket = { git = "https://github.com/SergioBenitez/Rocket", rev = "91f6288ea4aeb3d5a502b2f18b2b9677a85463ea", features = ["json"] }
 rusoto_core = { version = "0.48.0", optional = true }
 rusoto_s3 = { version = "0.48.0", optional = true }
-semver = "0.11.0"
+semver = "1.0.17"
 serde = { version = "1.0.120", features = ["derive"] }
 serde_json = "1.0.61"
 tantivy = "0.16.1"

wally-registry-backend/src/main.rs

@@ -10,6 +10,7 @@ mod storage;
 #[cfg(test)]
 mod tests;
 
+use std::collections::HashSet;
 use std::convert::TryInto;
 use std::io::{Cursor, Read, Seek};
 use std::sync::RwLock;
@@ -38,7 +39,8 @@ use rocket::{
     State,
 };
 use rocket::{Build, Request, Response};
-use semver::Version;
+use semver::{Version, VersionReq};
+use serde::Serialize;
 use serde_json::json;
 use storage::StorageMode;
 use zip::ZipArchive;
@@ -104,6 +106,37 @@ async fn package_info(
     Ok(Json(serde_json::to_value(metadata)?))
 }
 
+// TODO! Move this to a proper home in some analytics module
+#[derive(Serialize)]
+struct AnalyticsMetadata {
+    dependents: Vec<(PackageName, VersionReq)>,
+}
+
+#[get("/v1/package-analytics/<scope>/<name>")]
+async fn package_analytics(
+    _read: Result<ReadAccess, Error>,
+    search_backend: &State<RwLock<SearchBackend>>,
+    scope: String,
+    name: String,
+) -> Result<Json<serde_json::Value>, Error> {
+    _read?;
+
+    let package_name = PackageName::new(scope, name)
+        .context("error parsing package name")
+        .status(Status::BadRequest)?;
+
+    if let Ok(search_backend) = search_backend.read() {
+        Ok(Json(serde_json::to_value(AnalyticsMetadata {
+            dependents: search_backend.get_dependents(&package_name),
+        })?))
+    } else {
+        Err(
+            format_err!("Unexpected error fetching analytics metadata. Try again later.")
+                .status(Status::InternalServerError),
+        )
+    }
+}
+
 #[get("/v1/package-search?<query>")]
 async fn package_search(
     search_backend: &State<RwLock<SearchBackend>>,
@@ -254,7 +287,8 @@ pub fn server(figment: Figment) -> rocket::Rocket<Build> {
                 package_contents,
                 publish,
                 package_info,
-                package_search
+                package_search,
+                package_analytics,
             ],
         )
         .manage(storage_backend)